Print original input order of dictionary in python

Question

How do I print out my dictionary in the original order I had set up?

If I have a dictionary like this:

smallestCars = {'Civic96': 12.5, 'Camry98':13.2, 'Sentra98': 13.8}

and I do this:

for cars in smallestCars:
    print cars

it outputs:

Sentra98
Civic96
Camry98

but what I want is this:

Civic96
Camry98
Sentra98

Is there a way to print the original dictionary in order without converting it to a list?

But why the order changed when printing it, Why it is not printing as assigned — Vijay Panchal, Aug 20 '19 at 09:33

score 21 · Accepted Answer · edited Nov 21 '13 at 01:44

A regular dictionary doesn't have order. You need to use the OrderedDict of the collections module, which can take a list of lists or a list of tuples, just like this:

import collections

key_value_pairs = [('Civic86', 12.5),
                   ('Camry98', 13.2),
                   ('Sentra98', 13.8)]
smallestCars = collections.OrderedDict(key_value_pairs)

for car in smallestCars:
    print(car)

And the output is:

Civic96
Camry98
Sentra98

score 2 · Answer 2 · answered Nov 21 '13 at 01:23

2

Dictionaries are not required to keep order. Use OrderedDict.

answered Nov 21 '13 at 01:23

Amadan

191,408
23
240
301

score 2 · Answer 3 · answered Nov 21 '13 at 03:15

2

>>> for car in sorted(smallestCars.items(),key=lambda x:x[1]):
...     print car[0]
... 
Civic96
Camry98
Sentra98

answered Nov 21 '13 at 03:15

sinceq

844
8
12

score 1 · Answer 4 · answered Nov 21 '13 at 01:32

When you create the dictionary, python doesn't care about in what order you wrote the elements and it won't remember the order after the object is created. You cannot expect it(regular dictionary) to print in the same order. Changing the structure of your code is the best option you have here and the OrderedDict is a good option as others stated.

score 0 · Answer 5 · answered Jan 16 '18 at 17:51

You can use a tuple (nested) array to do this:

smallestCars = [['Civic86', 12.5],
               ['Camry98', 13.2],
               ['Sentra98', 13.8]]

for car, size in smallestCars:
    print(car, size)

# ('Civic86', 12.5)
# ('Camry98', 13.2)
# ('Sentra98', 13.8)

Print original input order of dictionary in python

5 Answers5

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